Semiconductor substrates are often subjected to thermal treatment following a material process such as deposition of materials on a substrate containing features formed in the surface thereof. Temperature uniformity across the semiconductor substrate is critical during the thermal treatment to effectively reflow material deposited on the substrate during the deposition phase and provide a more conformal distribution of the material on the substrate and within the features. Some reflow chambers use a reflective surface to direct radiation toward the backside of the semiconductor substrate. However, space constraints within the reflow chamber substantially limit the area of the reflecting surface, adversely affecting the temperature uniformity of the semiconductor substrate.
Thus, the inventors have provided apparatus for processing substrates that, in at least some embodiments, improves temperature uniformity across a substrate.